#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;
const int N = 310;
int c[N];
int main()
{
	int n, a, b;
	cin >> n >> a >> b;
	for (int i = 1; i <= n; i++)
		cin >> c[i];
	for (int i = 1; i <= n; i++)
	{
		if (a + b == c[i])
			cout << i << endl;
	}
	return 0;
}